1. Field of the Invention
The invention relates to a bistable solenoid valve with a locking mechanism that alternates between two positions to open and close the valve.
2. The Prior Art
A bistable solenoid valve with an immersion core, which can be actuated by one single magnet winding and reset by spring force, is known from DE-OS 38 10 154, said immersion core being supported in a core guide tube connected with the controlled medium. The magnetic circuit contains a permanent magnet, the field of which is alternately intensified and weakened by successive dc-voltage switching pulses of different polarity. Such a solenoid valve, as opposed to a comparable monostable solenoid valve, has the advantage that it requires only short switching pulses in each case; that its energy consumption is low on account of said fact; and that accordingly, the amount of heat collected, which has to be taken into account for its design, is low as well, if not even negligible. On the other hand, the switching system of the aforementioned, known solenoid valve requires relatively great expenditure with respect to material and manufacture because it requires a balancing of forces and, therefore, relatively narrow tolerances to be complied with. Furthermore, the bipolar switching means required for its operation are relatively costly.
The invention is based on the problem of creating a solenoid valve that is simpler and can be manufactured at more favorable cost, accordingly, and which, furthermore, is extremely economical with respect to energy consumption.
A bistable electromagnetic switching system with one single magnet winding and an immersion core, the latter being resettable by spring force, is known already from DE-OS 1 464 419. Said system is to be preferably used for electric switches. For fixing the immersion core in the one of its two final positions, said switching system has an engageable and releasable locking mechanism with a first detent member guided lengthwise, and a second detent member displaceable lengthwise against the first detent member and rotatable in an overlift position around an angle graduation. A spiral pressure spring causes face-side cam gear rims of the two detent members to engage each other--in a way as similarly used in connection with some retractable pens.
The invention is based on the consideration that such a switching system according to aforementioned DE-OS 1 464 419 is, in connection with some additional measures, suitable for solving the above problem in a special way.